Expression analysis of a-smooth muscle actin and tenascin-C in the periodontal ligament under orthodontic loading or in vitro culture

α-smooth muscle actin （α-SMA） and tenascin-C are stress-induced phenotypic features of myofibroblasts. The expression levels of these two proteins closely correlate with the extracellular mechanical microenvironment. We investigated how the expression of α-SMA and tenascin-C was altered in the periodontal ligament （PDL） under orthodontic loading to indirectly reveal the intrinsic mechanical microenvironment in the PDL. In this study, we demonstrated the synergistic effects of transforming growth factor-β1 （TGF-β1） and mechanical tensile or compressive stress on myofibroblast differentiation from human periodontal ligament cells （hPDLCs）. The hPDLCs under higher tensile or compressive stress significantly increased their levels of α-SMA and tenascin-C compared with those under lower tensile or compressive stress. A similar trend was observed in the tension and compression areas of the PDL under continuous light or heavy orthodontic load in rats. During the time-course analysis of expression, we observed that an increase in α-SMA levels was matched by an increase in tenascin-C levels in the PDL under orthodontic load in vivo. The time-dependent variation of α-SMA and tenascin-C expression in the PDL may indicate the time-dependent variation of intrinsic stress under constant extrinsic loading.

Epigallocatechin-3-gallate suppresses transforming growth factor-beta signaling by interacting with the transforming growth factor-beta typeⅡreceptor

AIM: To investigate the(-)-epigallocatechin-3-gallate(EGCG) binding to transforming growth factor-β(TGF-β) type Ⅱ receptor(TGFRⅡ).METHODS: The expression of α-smooth muscle actin(α-SMA) was used as a marker for fibrotic change inhuman lung fibroblast MRC-5 cells. The α-SMA expression level was determined by western blotting and immunohistological analysis. We examined whether the anti-fibrotic effects of EGCG on MRC-5 cells was dependent on antioxidant mechanism by using edaravone and N-acetylcysteine(NAC). The suppression effects of EGCG on Smad2/3 activation were studied by confocal fluorescence microscopy. The binding of EGCG to recombinant TGFRⅡ protein was analyzed by immunoprecipitation and affinity chromatography.RESULTS: When MRC-5 cells were treated with TGF-β, EGCG decreased the expression of α-SMA in a dose dependent manner, whereas catechin did not influence the α-SMA expression in the cells. Except for EGCG, antioxidant compounds(e.g., edaravone and NAC) had no effects on the TGF-β-induced α-SMA expression. Nuclear localization of phosphorylated Smad2/3 was observed after TGF-β treatment; however, EGCG treatment attenuated the nuclear transportation of Smad2/3 in the presence or absence of TGF-β. After a TGFRⅡ expression vector was introduced into COS-7 cells, cell lysates were untreated or treated with EGCG or catechin. The immunoprecipitation experiments using the lysates showed that EGCG dose-dependently bound to TGFRⅡ and that catechin did not at all. Affinity chromatography study indicated that EGCG would bind to TGFRⅡ.CONCLUSION: Our results demonstrate that EGCG interacts with TGFRⅡ and inhibits the expression of α-SMA via the TGF-β-Smad2/3 pathway in human lung fibroblast MRC-5 cells.

Dynamic Variation of RAS on Silicotic Fibrosis Pathogenesis in Rats

The dynamic variation of renin-angiotensin system (RAS) in silicosis remains unclear.Seventy Wistar rats were divided into 7 groups including control group,silicosis groups (inhaling SiO2 for 2,4,8,16 and 24 weeks,respectively) and Captopril (Cap) group.Rat lung primary fibroblasts were divided into control group,SiO2-stimulated group (0,0.5,1,3,6,12,24 and 48 h) and Cap group.The silicotic nodules were formed and collagens were deposited gradually in silicosis group observed by haematoxylin and eosin (HE) staining and Van Gieson (VG) staining.Cap relieved the lung fibrosis and collagen deposition.Immunohistochemistry indicated the positive expression of α-smooth muscle actin α-SMA) was increased gradually in silicotic rat lung tissue.Western blotting revealed the expression of collagen type Ⅰ(Col Ⅰ) and α-SMA was up-regulated in silicotic rat lung tissue and fibroblasts stimulated by SiCh.Cap decreased the expression of Col Ⅰ and α-SMA in silicotic rat lung tissue and fibroblasts stimulated by SiCh.Western blotting also demonstrated the expression of angiotensin-converting enzyme (ACE) and angiotensin Ⅱ type 1 receptor (ATI) was increased,and the expression of ACE2 and Mas was decreased gradually in silicotic rat lung tissue and fibroblasts stimulated by SiCh.ELISA showed the serum levels of ACE and angiotensin Ⅱ(Ang Ⅱ) were also increased and ACE2 and Ang (1 -7) were decreased in the silicosis group.Treatment with Cap decreased the expression levels of ACE,Ang Ⅱ and ATI,and increased the expression levels of ACE2,Ang (1-7) and Mas.These findings suggested that an imbalance between ACE-Ang Ⅱ-AT1 axis and ACE2-Ang (l-7)-Mas axis may participate in the development of silicosis.

Gardenia jasminoides attenuates hepatocellular injury and fibrosis in bile duct-ligated rats and human hepatic stellate cells

AIM:To investigate the anti-hepatofibrotic effects of Gardenia jasminoides in liver fibrosis.METHODS:Male Sprague-Dawley rats underwent common bile duct ligation(BDL) for 14 d and were treated with Gardenia jasminoides by gavage.The ef-fects of Gardenia jasminoides on liver fibrosis and the detailed molecular mechanisms were also assessed in human hepatic stellate cells(LX-2) in vitro.RESULTS:Treatment with Gardenia jasminoides decreased serum alanine aminotransferase(BDL vs BDL + 100 mg/kg Gardenia jasminoides,146.6 ± 15 U/L vs 77 ± 6.5 U/L,P = 0.0007) and aspartate aminotransferase(BDL vs BDL + 100 mg/kg Gardenia jasminoides,188 ± 35.2 U/L vs 128 ± 19 U/L,P = 0.005) as well as hydroxyproline(BDL vs BDL + 100 mg/kg Gardenia jasminoides,438 ± 40.2 μg/g vs 228 ± 10.3 μg/g liver tissue,P = 0.004) after BDL.Furthermore,Gardenia jasminoides significantly reduced liver mRNA and/or protein expression of transforming growth factor β1(TGF-β1),collagen type?Ⅰ?(Col?Ⅰ) and α-smooth muscle actin(α-SMA).Gardenia jasminoides significantly suppressed the upregulation of TGF-β1,Col?Ⅰand α-SMA in LX-2 exposed to recombinant TGF-β1.Moreover,Gardenia jasminoides inhibited TGF-β1-induced Smad2 phosphorylation in LX-2 cells.CONCLUSION:Gardenia jasminoides exerts antifibrotic effects in the liver fibrosis and may represent a novel antifibrotic agent.

Smoothelin,a new marker to determine the origin of liver fibrogenic cells

AIM:To explore this hypothesis that smooth muscle cells may be capable of acquiring a myofibroblastic phenotype,we have studied the expression of smoothelin in fibrotic conditions.METHODS:Normal liver tissue(n=3)was obtained from macroscopically normal parts of hepatectomy,taken at a distance from hemangiomas.Pathological specimens included post-burn cutaneous hypertrophic scars(n=3),fibrotic liver tissue(n=5),cirrhotic tissue(viral and alcoholic hepatitis)(n=5),and hepatocellular carcinomas(n=5).Tissue samples were fixed in 10%formalin and embedded in paraffin for immunohistochemistry or were immediately frozen in liquid nitrogen-cooled isopentane for confocal microscopy analysis.Sections were stained with antibodies against smoothelin,which is expressed exclusively by smooth muscle cells,andα-smooth muscle actin,which is expressed by both smooth muscle cells and myofibroblasts.RESULTS:In hypertrophic scars,α-smooth muscle actin was detected in vascular smooth muscle cells and in numerous myofibroblasts present in and around nodules,whereas smoothelin was exclusively expressed in vascular smooth muscle cells.In the normal liver,vascular smooth muscle cells were the only cells that expressα-smooth muscle actin and smoothelin.In fibrotic areas of the liver,myofibroblasts expressingα-smooth muscle actin were detected.Myofibroblasts co-expressingα-smooth muscle actin and smoothelin were observed,and their number was slightly increased in parallel with the degree of fibrosis(absent in liver with mild or moderate fibrosis;5%to 10%positive in liver showing severe fibrosis).In cirrhotic septa,numerous myofibroblasts co-expressedα-smooth muscle actin and smoothelin(more than 50%).In hepatocellular carcinomas,the same pattern of expression forα-smooth muscle actin and smoothelin was observed in the stroma reaction surrounding the tumor and around tumoral cell plates.In all pathological liver samples,α-smooth muscle actin and smoothelin were co-expressed in vascular smooth muscle cells.CONCLUSION:During development of advanced liver fibrosis,a subpopulation of myofibroblasts expressing smoothelin may be derived from vascular smooth muscle cells,illustrating the different cellular origins of myofibroblasts.

The ROCK pathway inhibitor Y-27632 mitigates hypoxia and oxidative stress-induced injury to retinal Müller cells

Rho kinase （ROCK） was the first downstream Rho effector found to mediate RhoA-induced actin cytoskeletal changes through effects on myosin light chain phosphorylation. There is abundant evidence that the ROCK pathway participates in the pathogenesis of retinal endothelial injury and proliferative epiretinal membrane traction. In this study, we investigated the effect of the ROCK pathway inhibitor Y-27632 on retinal Müller cells subjected to hypoxia or oxidative stress. Müller cells were subjected to hypoxia or oxidative stress by exposure to CoCl2 or H2O2. After a 24-hour treatment with Y-27632, the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide assay was used to assess the survival of Müller cells. Hoechst 33258 was used to detect apoptosis, while 2′,7′-dichlorodihydrofluorescein diacetate was used to measure reactive oxygen species generation. A transwell chamber system was used to examine the migration ability of Müller cells. Western blot assay was used to detect the expression levels of α-smooth muscle actin, glutamine synthetase and vimentin. After treatment with Y-27632, Müller cells subjected to hypoxia or oxidative stress exhibited a morphology similar to control cells. Y-27632 reduced apoptosis, α-smooth muscle actin expression and reactive oxygen species generation under oxidative stress, and it reduced cell migration under hypoxia. Y-27632 also upregulated glutamine synthetase expression under hypoxia but did not impact vimentin expression. These findings suggest that Y-27632 protects Müller cells against cellular injury caused by oxidative stress and hypoxia by inhibiting the ROCK pathway.

Daikenchuto (Da-Jian-Zhong-Tang) ameliorates intestinal fibrosis by activating myofibroblast transient receptor potential ankyrin 1 channel

AIM To investigate the anti-fibrotic effects of the traditional oriental herbal medicine Daikenchuto(DKT) associated with transient receptor potential ankyrin 1(TRPA1) channels in intestinal myofibroblasts. METHODS Inflammatory and fibrotic changes were detected in a2,4,6-trinitrobenzenesulfonic acid(TNBS) chronic colitis model of wild-type and TRPA1-knockout(TRPA1-KO) mice via pathological staining and immunoblotting analysis.Ca^(2+) imaging experiments examined the effects of DKT and its components/ingredients on intestinal myofibroblast(In Myo Fib) cell TRPA1 channel function.Profibrotic factors and transforming growth factor (TGF) -β1-associated signaling were tested in an In Myo Fib cell line by q PCR and immunoblotting experiments.Samples from non-stenotic and stenotic regions of the intestines of patients with Crohn’s disease (CD) were used for pathological analysis. RESULTS Chronic treatment with TNBS caused more severe inflammation and fibrotic changes in TRPA1-KO than in wild-type mice.A one-week enema administration of DKT reduced fibrotic lesions in wild-type but not in TRPA1-KO mice.The active ingredients of DKT,i.e.,hydroxyα-sanshool and 6-shogaol,induced Ca^(2+) influxes in In Myo Fib,and this was antagonized by co-treatment with a selective TRPA1 channel blocker,HC-030031.DKT counteracted TGF-β1-induced expression of TypeⅠcollagen andα-smooth muscle actin (α-SMA) ,which were accompanied by a reduction in the phosphorylation of Smad-2 and p38-mitogen-activated protein kinase (p38-MAPK) and the expression of myocardin.Importantly,24-h incubation with a DKT active component Japanese Pepper increased the m RNA and protein expression levels of TRPA1 in In Myo Fibs,which in turn negatively regulated collagen synthesis.In the stenotic regions of the intestines of CD patients,TRPA1 expression was significantly enhanced.CONCLUSION The effects of DKT on the expression and activation of the TRPA1 channel could be advantageous for suppressing intestinal fibrosis,and benefit inflammatory bowel disease treatment.

Effects of transforming growth factor β2 and connective tissue growth factor on induction of epithelial mesenchymal transition and extracellular matrix synthesis in human lens epithelial cells

AIM:To Investigate the effects of transforming growth factorβ2(TGF-β2)and connective tissue growth factor(CTGF)on transdifferentiation of human lens epithelial cells(HLECs)cultured in vitro and synthesis of extracellular matrix(ECM).METHODS:HLECs were treated with TGF-β2(0,0.5,1.0,5,10μg/L)and CTGF(0,15,30,60,100μg/L)for different times(0,24,48,72h)in vitro and the expression ofα-smooth muscle actin(α-SMA),the main component of the extracellular matrix typeⅠcollagen(Col-1)and fibronectin(Fn)were measured by using real-time polymerase chain reaction(PCR)and western-blot.RESULTS:TGF-β2 and CTGF significantly increased expression ofα-SMA mRNA and protein(P【0.05,P【0.001),Fn mRNA and protein(P【0.001),Col-1 mRNA and protein(P【0.001).TGF-β2 could induce HLECs expression of CTGF mRNA and protein in dosedependent manner(P【0.05,P【0.001).TGF-β2 and CTGF could induce HLECs to expressα-SMA,Fn and Col-1 in time-dependent manner.Each time of TGF-β2and CTGF induced HELCs expression ofα-SMA,Fn,Col-1 mRNA and protein was significant increase compared with control(P【0.05,P【0.001).CONCLUSION:TGF-β2 and CTGF could induce HLECs epithelial mesenchymal transition and ECM synthesis.

Effect of NF-κB p65 antisense oligodeoxynucleotide on transdifferentiation of normal human lens epithelial cells induced by transforming growth factor-β2

AIM：To study the inhibition of nuclear factor kappa-B p65（NF-κB p65）antisense oligodeoxynucleotide（ASODN）on transdifferentiation of normal human lens epithelial cells induced by transforming growth factor-β2（TGF-β2）.·M ETHODS：NF-κBp65ASODNand NF-κBp65missense oligodeoxynucleotide（MSODN）were designed and synthesized.Human lens epithelial cell line（HLE B-3）cells were prepared for study and divided into 7 groups.Control group was HLE B-3 cells cultured in dulbecco’s modified eagle medium（DMEM）.T1,T2,and T3 group were HLE B-3 cells cultured in DMEM with 10 ng/m L TGF-β2 for 6h,12h,24h respectively.A＋T group was HLE B-3 cells cultured with 10 ng/m L TGF-β2for 24h after transfected by NF-κB p65 ASODN for 24h.M＋T group was HLE B-3 cells cultured with 10 ng/m L TGF-β2 for 24h after transfected by NF-κB p65 MSODN for 24h.The negative control group was HLE B-3 cells cultured with 10 ng/m L TGF-β2 for 24h after cultured with transfer agent（Hi Per Fect）for 24h.Cell morphology was observed at different time points using an inverted microscope.The expression of NF-κB p65 m RNA was detected with reverse transcription-polymerase chain reaction（RT-PCR）,and the expression ofα-smooth muscle actin（α-SMA）protein was assayed with ELISA.·RESULTS：With the TGF-β2 stimulation prolongation,the expression of NF-κB p65 m RNA and a-SMA protein increased in T1,T2,T3 groups compared with the control group,and the difference was statistically significant（〈0.05）.NF-κB p65 ASODN lowered the expression of NF-κB p65 m RNA andα-SMA protein induced by TGF-β2.NF-κB p65 MSODN and Hi Per Fect did not lower the expression of NF-κB p65 m RNA andα-SMA protein induced by TGF-β2.The difference between control group and A＋T group was not statistically significant（〉0.05）,but the difference among A＋T group and other groups was statistically significant（〈0.05）.·CONCLUSION：NF-κB p65 ASODN could lower the expression of NF-κB p65 m RNA andα-SMA protein induced by TGF-β2,and antagonized TGF-β2-induced transdifferentiation of HLE B-3.NF-κB p65ASODN could be used as a new biological therapeutic target of posterior capsular opacification.

PDGF/ROCK通路介导的肌成纤维细胞分化在大鼠矽肺形成中的作用

目的:探讨PDGF/Rock通路介导的肌成纤维细胞分化在大鼠矽肺纤维化形成中的作用。方法:采用非暴露式气管二氧化硅混悬液灌注法制备大鼠矽肺模型,SPF级健康成年Wistar大鼠40只随机分为四组:模型对照4周组、模型对照8周组、矽肺模型4周组、矽肺模型8周组,每组10只。Western blot检测肺组织内α-SMA、phosphoPDGF-β、ROCK、Ⅰ型和Ⅲ型胶原蛋白的表达。结果:大鼠矽肺模型制备成功。与相应对照组相比,矽肺模型组大鼠肺组织内α-SMA、phospho-PDGFR-β、Rock以及Ⅰ型和Ⅲ型胶原蛋白表达均明显增加,比较差异有统计学意义(P<0.05)。结论:PDGF介导的ROCK信号转导通路可能通过促进大鼠肌成纤维细胞转化而促进矽肺大鼠肺组织内的胶原合成,进而促进矽肺纤维化的形成。

Preventive approach against drug-induced pulmonary fibrosis through the suppression of epithelial-mesenchymal transition

A number of drugs induce pulmonary injury and subsequently lead to serious lung diseases such as pulmonary fibrosis as the adverse drug reactions.However,an effective preventive approach against drug-induced pulmonary fibrosis has not been established due to poor understanding of common preventive targets in a variety of drugs showing pulmonary toxicity.Epithelial-mesenchymal transition(EMT),a cellular phenotypic change of the epithelial to mesenchymal state,contributes to the development of pulmonary fibrosis through the conversion of damaged alveolar epithelium into myofibroblasts.As several drugs with pulmonary toxicity have been reported to induce EMT,EMT serves as a bridge between the drugs and pulmonary fibrosis.Accumulated evidence supports the potential of EMT as a preventive target against drug-induced pulmonary fibrosis.Additionally,since there are mechanistic differences between the main pharmacological effect and EMT induced by the drug,prevention based on EMT suppression would be possible and would contribute to continuous clinical treatment with the drug to avoid EMT-mediated serious pulmonary fibrosis.Furthermore,targeting EMT seems to be adequate for exerting a preventive effect since EMT in damaged alveolar epithelial cells occurs prior to the development of the pathophysiological state of the whole lung in a bleomycin-induced lung injury rat model.This viewpoint deals with the benefits and perspectives of preventive approaches against druginduced pulmonary fibrosis through the suppression of EMT,which has rarely been addressed.

Protective Effect of Hydroxysafflor Yellow A on Bleomycin-Induced Pulmonary Inflammation and Fibrosis in Rats

Objective： To observe the effect of hydroxysafflor yellow A （HSYA）, an active ingredient of a traditional Chinese herbal medicine Carthamus tinctorius L., on lung inflammation and pulmonary fibrosis induced by bleomycin （BLM） in rats. Methods： Animals were divided into 6 groups including normal group, model group, three HSYA groups and dexamethasone （DXM） group. Three doses of HSYA （35.6, 53.3, and 80.0 mg？kg–1？day–1） were intraperitoneally （i.p.） injected in rats for 3 weeks after BLM administration and DXM was used as the positive control （n=8 or 12）. Arterial blood gas was assayed and morphological changes were observed. Lung mRNA expressions of tumor necrosis factor （TNF）-α, interleukin （IL）-1β, IL-6 and some cytokines in lung tissue were detected by real-time polymerase chain reaction. Nuclear factor-κB p65 or α-smooth muscle actin （α-SMA） protein distribution in rat lung tissue was observed by immunohistochemistry. Results： On the 7th day after BLM administration, lung tissue showed serious inflammation. Treatment with HSYA or DXM ameliorated lung inflammation. After treatment with HSYA or DXM, oxygen partial pressure （PaO2） increased （HSYA 80.0 mg？kg–1, P〈0.01） and CO2 partial pressure （PaCO2） decreased （HSYA 53.3, 80.0 mg？kg–1, P〈0.05）. Moreover, the mRNA expression of TNF-α, IL-1β, and IL-6; and the number of NF-κB p65 positive cells was lower in HSYA 53.3 and 80.0 mg？kg–1 groups than those in the model group （all P〈0.05）. Twenty-one days after BLM administration, HSYA or DXM treatment ameliorated fibrosis, increased PaO2 （HSYA 53.3, 80.0 mg？kg–1, P〈0.01）, and decreased PaCO2 （53.3 and 80.0 mg？kg–1, P〈0.05）. Further, the mRNA expression of TGF-β1, α-SMA, and collagen Ⅰ as well as the number of α-SMA positive cells increased in the model group and HSYA can attenuate these changes （53.3, 80.0 mg？kg–1, P〈0.05）. Hematoxylin and eosin and Masson＇s trichrome staining indicated that the fibrosis and collagen deposition were ameliorated in HSYA groups （53.3, 80.0 mg？kg–1, P〈0.05）. Conclusion： HSYA could alleviate acute lung inflammation and chronic pulmonary fibrosis induced by BLM in rats.

Effect of Quyu Chencuo Formula(去菀陈莝方)on Renal Fibrosis in Obstructive Nephropathy Rats

Objective: To observe the effect of Quyu Chencuo Formula(去菀陈莝方, QCF) on renal fibrosis in rats with obstructive nephropathy. Methods: Twenty-four rats were randomly divided into three groups, 4 for sham operation as the control group, 10 for unilateral ureteral obstruction(UUO) model group, and the rest 10 for QCF treating UUO model group. All rats were sacrificed under 3% pentobarbital(50 mg/kg) anesthesia on the 14 th day after surgery, then the right kidney samples of rats were harvested for hematoxylin eosin(HE) staining and Masson staining to observe the renal pathological changes. Immunohistochemistry and Western blotting were used to examine the expression of transforming growth factor β1(TGF-β1), and real-time polymerase chain reaction(RT-PCR) was employed to examine the expressions of TGF-β1, α-smooth muscle actin(α-SMA) and E-cadherin mRNA. Results: HE and Masson staining showed that the renal interstitial of the rats in the control group had no significant fibrotic lesion; in the model group, there were obvious interstitial fibrosis; for the QCF group, there were epithelial cell necrosis, infiltration of lymphocytes and mononuclear cells, aggravated interstitial fibrosis in varied degrees, but the pathological changes were less in the QCF group than in the model group. The immunohistochemistry and Western blotting results showed that the TGF-β1 expression was increased significantly in the model group, while decreased significantly in the QCF group(P<0.05); RT-PCR showed that the mRNA expression of α-SMA and TGF-β1 increased significantly in the model group, while both were significantly decreased in the QCF group compared with the model group(P<0.05). The mRNA expression of E-cadherin was decreased significantly in the model group, and it was significantly increased in the QCF group as compared with the model group(P<0.05). Conclusion: QCF may improve renal fibrosis by regulating the expressions of TGF-β1, α-SMA and E-cadherin, and prevent the progress of kidney fibrosis.